A federal route redesignation and a new $143.5 million drainage contract are moving Syracuse’s I-81 Viaduct Project deeper into Phase Two, even as motorists are told not to expect immediate changes to highway signs or traffic patterns.

The I-81 Viaduct Project reached two new milestones on Sept. 22, according to Gov. Kathy Hochul’s office and the New York State Department of Transportation. The Federal Highway Administration approved the redesignation of Interstate 481 as the new Interstate 81, while the existing I-81 corridor through Syracuse is set to become Business Loop 81. At the same time, NYSDOT awarded Contract 6a, a $143.5 million project centered on a new underground stormwater trunkline beneath downtown Syracuse.

What changed with I-81 and I-481?

The biggest administrative change is the federal approval to make today’s I-481 the future I-81 around Syracuse. The current I-81 route through the city will become Business Loop 81 between the northern and southern I-81/I-481 interchanges.

That change is a key step toward removing the 1.4-mile elevated viaduct through Syracuse and replacing it with the street-level Community Grid. The state says motorists should not expect an immediate switch. NYSDOT is still developing a changeover plan for signs, route numbers and traffic operations.

For drivers, that means the project is moving forward on paper and in construction, but the roads will continue to look familiar for now.

New $143.5 million contract targets flooding and drainage

Contract 6a will build a roughly one-mile underground trunkline designed to collect stormwater from reconstructed roads and bridges. State officials say the work is intended to reduce flooding, separate stormwater from sewage and lessen overflow into Onondaga Creek and Onondaga Lake.

The pipe will measure about eight feet by 10 feet and require excavation as deep as 25 feet in some locations. Planned work will run beneath portions of Almond Street, East Water Street, South State Street, Erie Boulevard East, North Salina Street and Herald Place.

Five local streets, totaling about 2.5 lane miles, are also scheduled for reconstruction or rehabilitation. The work includes new sidewalks, shared-use paths, eight replacement traffic signals, lighting, signs, striping and trees.

Why the drainage work matters

The highway project is also being used to replace aging infrastructure below city streets. Contract 6a is part of a broader effort to create separate systems for stormwater and sewage in parts of Syracuse.

NYSDOT Commissioner Marie Therese Dominguez said the work below ground is expected to have “huge, visible impacts above ground.” State officials say the drainage upgrades should reduce the risk of stormwater overwhelming local systems during heavy rain.

The new trunkline follows earlier drainage and sewer work tied to other I-81 contracts, including a half-mile drainage line along Erie Boulevard East and additional sewer and stormwater improvements in other parts of the project area.

Phase Two is now focused on removing the viaduct

Phase One began in 2023 and focused heavily on rebuilding the northern and southern I-81/I-481 interchanges and preparing I-481 to carry through interstate traffic. In June, the state announced completion of major work on those interchanges, a milestone Utica Phoenix previously covered in its report on the $366 million interchange work.

Phase Two shifts attention toward removing the elevated viaduct and building the Community Grid. In July, NYSDOT announced a separate $2.1 billion sixth contract to reconstruct and realign part of I-690, rebuild local streets and create new access points to downtown Syracuse.

Contract 6a is the second contract awarded under Phase Two. It was separated from the larger Contract 6 so the drainage work could be bid and managed on its own.

What the project means for Central New York travelers

The I-81 work is centered in Syracuse, but its effects reach beyond city limits. The corridor connects drivers to downtown, University Hill, hospitals, Syracuse University, I-690 and routes leading north and south through Central New York.

For Mohawk Valley residents who travel to Syracuse for medical care, college events, shopping, work or air travel, construction can mean changing ramps, lane shifts and detours. NYSDOT continues to issue traveler advisories as work progresses.

The state says the long-term plan is to move high-speed interstate traffic around downtown while creating a lower-speed street network through the city. Supporters of the Community Grid have argued that it can reconnect neighborhoods divided by the viaduct. The near-term tradeoff is years of construction, deep excavation and traffic disruption for residents, businesses and commuters along the project corridor.

What happens next?

NYSDOT is preparing a broader transition plan for the route redesignation. The agency also plans an open house for residents and commuters focused on Contract 6a, although the Sept. 22 announcement did not list a date.

Drivers should continue using existing highway signs and checking current traffic advisories before traveling through active work zones. The state’s I-81 project website and 511NY provide ongoing construction and traffic information.

Gov. Hochul called the redesignation of I-481 “a critically important step” in the overall project. The next major test will be how smoothly the state manages the transition from the existing viaduct system to the Community Grid while maintaining access through one of Central New York’s busiest transportation corridors.

Sources: Office of Gov. Kathy Hochul, Sept. 22, 2026; New York State Department of Transportation, July 3, 2026.